Combined tenter clamp and needle chain for textile tentering machines



Nov. 29, 1955 H. A. BUYSCH ET COMBINED TENTER CLAMP AND NEEDLE CHAIN FOR TEXTILE TENTERING MACHINES Filed Sept. 10, 1954 atent fiice 2,724,888 Patented Nov. 29, 1955 COMBINED TENTER CLAMP AND NEEDLE CHAIN FOR TEXTILE TENTERING MACHINES Heinrich A. Buysch, Aachen-80ers, and Rolf Bochmann, Aachen, Germany, assignors to H. Krantz Siihne, Aachen, Germany, a firm This invention relates to a combined tenter clamp and needle chain for textile tentering machines.

In chains of this kind, in addition to stationary needle strips, adjustable needle strips have already been proposed which, when changing over from needle to clamp travel, can be turned over by 180 from the position for needle travel, level with the clamp table, or which can be swung upwards or downwards into inoperative position. In particular for needle strips adapted to swing downwards into the inoperative position, a construction has already been proposed in which a locking lever is pivotally connected to the swinging arm of the needle strip, which locking lever on swinging the needle strip up into the working position, engages on the clamp table under the action of a spring and thereby locks the needle strip in the operating position for needle travel. In this construction only an extremely restricted space is left, between a run-on snout on the locking lever and the movable part or feeler latch of the clamp, for the control rail designed to disconnect the locking lever from its engagement with the clamp table, so that there is a danger that the control rail may strike violently against the feeler latches in the event of slight changes of position or of vibration occurring during operation.

In contradistinction thereto, the present invention provides a combined tenter clamp and needle chain, in which the locking lever is so shaped that on the one hand on swinging upwards and thereby locking the needle strip it simultaneously opens the feeler latch, and on the other hand by the closing of the feeler latch it is released from the locking position and freed, together with the needle strip, to swing down into the inoperative position which does not hinder travel with tenter clamps. Thus, on the one hand, a control rail, which acts directly on the locking lever to be freed and which because of its thickness and the clearance that it requires can be accommodated only with difficulty due to the restricted space between the locking lever and the feeler latch, is avoided, and in its place use is made of a control rail acting on the control cam of the feeler latch of the clamp and lying opposite, or in some cases connected to, the customary opener rail of the tenter clamp, while on the other hand when travelling with needles the feeler latches are lifted ofi the clamp table in order to save their gripping blades.

The lifting of the feeler latches off the clamp table in tenter clamp chains is known per se, and has for example been proposed in order to avoid contact between the gripping blades of the clamp latches and the clamp table when running without load, i. e. when no fabric is gripped in the tenter clamps. Furthermore, lifting the feeler latches oil the clamp table when the machine is used for needle travel has already been proposed for combined tenter clamps with stationary needle strips. However, in that case the feeler latches are opened by swinging up a protective stirrup which covers the needle strips during clamp travel. Moreover, no consideration has been given to using the feeler latch in its turn for moving the protective stirrup into the covering position when changing over to clamp travel, but use is made for this purpose of the control thumb which also serves to swing up the protective stirrup.

In the tenter clamp and needle chain of the present invention the locking lever is not supported on the clamp table but, in order to preserve the latter, is supported by lateral locking snouts in notches provided beneath the clamp table in the fixed portion of the clamp, while an extended middle ram arm on the locking lever cooperates with the feeler latch of the clamp. The notches for the locking snouts of the locking lever may be formed by the receiving slots with which known tenter clamps with stationary needle strips are provided for mounting the needle strips, so that these known tenter clamps can be subsequently equipped with the swingable needle strip of the invention instead of the stationary needle strip, without changing the basic shape of the tenter clamp elements.

The feeler latch of the lamp is advantageously provided, for the purpose of cooperation with the rain arm of the locking lever, with a toothed cam-like projection which serves as a pushing and sliding surface for the head of the ram arm and provides good transmission ratios over the entire range of the mutual force action of ram and feeler latch.

The spring acting on the locking lever and the needle strip supporting lever is preferably accommodated on both sides of a middle point of action for the levers, as a helical spring, on the swinging axis of the needle strip.

' to swing downwards into an inoperative position according to the invention and in which:

Figure 1 shows a tenter clamp and needle chain member in the position for needle travel, in side elevation and partly in section;

Figure 2 shows the same in end view; and

Figure 3 shows the tenter clamp and needle chain member in the position for clamp travel, with the needle strip swung into the inoperative position, in the same side elevation as in Fig. 1.

The tenter clamp body It carries in lateral brackets 2 for a longitudinal bar 3, on which the clamp table plate 4 is mounted, an axle 5 which is secured against longitudinal displacement and preferably also against rotation. Said axle forms the rocking axis for angular swinging arms 6 which are disposed on the outside of the brackets 2 of the table 4, and which carry at their ends, which are connected by a supporting bridge, the needle strip 7.

The apex parts of the angular swinging arms 6 carry a shaft 8 on which a locking lever 9 is pivotally mounted by means of two lateral bearing eyes It The locking lever 9 carries at its two side ends, on the inner surface, locking snouts 11 which engage in notches 12 of the brackets 2 beneath the clamp table 4. The notches 12 correspond to the slots provided in known and widely used clamp needle chains for fastening stationary needle strips. The movable part of the clamp consists of the feeler latch 15 with the gripping blade 16. The locking lever 9 tapers above the locking snouts 11 into a central ram arm 13, which acts on a cam-like projection 14 on the feeler latch 15 and in the position in which the locking lever 9 locks the needle strip 7 in its working position lifts the feeler latch 15 on the clamp table 4. This lifting-off is so adjusted with relation to the dropping of the locking snouts 11 into the notches 12 that it preferably occurs before locking commences. A restoration of the latch to its closed position brought about by a force exerted on the control thumb 21 of the feeler latch 15, therefore ensures the disengagement of the locking lever 9 out of the locking position before the latch reaches its closed position, and in consequence of this disengagement the locking lever 9 is swung downwards together with the needle strip 7 into the inoperative position beneath the table frame of the tenter clamp.

The locking lever is under the action of a helical spring 17 wound on the axle 5. Said spring consists of two halves wound in opposite directions, which in the middle are formed into a loop 18 constituting the movable spring end, and in this loop a pull wire 19 connected to the locking lever 9 is hooked, the free end of said wire which passes through the locking lever being shaped to form a circular loop 20 covering its passage aperture.

The description of the mode of operation will start from the operating position for clamp travel illustrated in Figure 3. The swinging arm 6 with the needle strip 7 and the locking lever 9 are swung by the spring 17 so far downwards beneath the table 4 of the clamp that they do not hinder the free admission of the drying medium, which for example is blown from below from nozzles, even to the edge of the web of fabric which is gripped by the clamp.

In order to change over the tenter chain from clamp travel to needle travel, the swinging arm 6 is swung up to bring the needle strip 7 into the working position by a control rail (not shown) moved into the path of movement of the lowered needle strip 7. The locking snouts 11 of the locking lever 9 slide on the horizontal tensioning surface 22 at the bottom of the brackets 2, whereby the spring 17 acting on the locking lever 9 is stressed to a rather greater extent. In the raised working position of the needle strip 7, the locking snouts 11 of the locking lever 9 come into line with the notches 12. The locking lever 9 thus swings under the action of the spring 17 into the position shown in Figures 1 and 2 and, through the engagement of its snouts 11 in the notches 12, locks the needle strip 7 in the operating position. While the lockin'g lever 9 is still sliding from the tensioning surfaces 20 to the notches 12, the ram arm 13 preferably already strikes on the proiection 14 on the feeler latch 15 and begins to open the latter, in order then to lift it further off the clamp table 4 in proportion as the locking snouts 11 drop into the notches 12. The change-over of the tentering chain from the position for clamp travel (Figure 3) into the operating position for needle travel (Figures 1 and 2) is thus completed. In order to return to clamp travel (Figure 3) the feeler latch 15 is pressed back nearly into its closed position by a butting rail moved into the path of movement of the control thumb 21. The projection 14 on the feeler latch 15 thus swings the locking lever 9 out of the supported position in the notches 12, whereby the locking lever and the swinging arms 6 with the needle strip 7 are caused to swing downwards under the action of the spring 17, until the bearing eyes 10 of the locking lever 9 come to rest against the bottom of the clamp table frame. In this lowered position the swingable parts 6, 7 and 9 are held by the spring 17 during clamp travel.

Having thus described our invention, what we claim is:

1. A combined tenter clamp and needle chain including a clamp body provided with a clamp table, a feeler latch pivotally supported by said body for clamping the selvedge of the fabric on said table, a needle strip swingably mounted in the clamp body for movement between a lower inoperative and an upper operative position, a locking lever for locking the needle strip in its upper operative position, arms supporting the needle strip, said locking lever being pivotally carried by said arms, a spring acting on said locking lever both in its upper lock- 4 ing position and its lower unlocked position, and means on said locking lever for opening the feeler latch during its movement into locking position and for releasing the locking lever from the locking position and for swinging it down together with the needle strip into inoperative position through the closing of the feeler latch.

2. A combined tenter clamp and needle chain as claimed in claim 1, in which the locking lever is provided on its middle portion with an extended ram arm cooperating with the 'feeler latch for opening it, and further provided on its inner surface with lateral locking snouts, said clamp body having notches therein beneath the clamp body in which said locking snouts are adapted to engage.

3. A combined tenter clamp and needle chain including a clamp body having a clamp table, a feeler latch pivotally supported by said body for clamping the selvedge of the fabric on said table, a needle strip swingably mounted in the clamp body for movement between a lower inoperative to an upper operative position, a locking lever for locking the needl strip in its upper operative position, arms supporting the needle strip, said locking lever being pivotally carried by said arms, a spring acting on the locking lever both in its upper locking position and its lower unlocked position, the locking lever having on its inner surface lateral locking snouts, said clamp body having notches therein in which said locking snouts are adapted to be engaged, said locking lever being provided on its middle portion with an extended ram arm cooperating with a cam-like projection on the feeler latch for opening the feeler latch and inversely returning the locking lever with the needle strip into inoperative position through the closing of the feeler latch.

4. A combined tenter clamp and needle chain as claimed in claim 3, in which the clamp body is provided with horizontal tensioning surfaces merging into the locking notches of the clamp body to receive the lateral locking snouts of the locking lever, with said snouts on sliding over the tcnsioning surfaces tensioning the spring acting on the locking lever.

5. A combined tenter clamp and needle chain, comprising a fixed part supporting the clamp table, a feeler latch constituting the movable part of the clamp and adapted to cooperate with the clamp table, swinging arms mounted underneath the clamp table on said fixed part, a needle strip carried by said swinging arms and a locking lever pivoted to the swinging arms, a spring acting on said locking lever, said spring being supported on the fixed part of the clamp and upon the raising of the needle strip, locking the needle strip in the working position and, upon disengagement from the supported position, swinging the needle strip downwards into inoperative position, the said locking lever being of such a shape that, on swinging upwards it opens the feeler latch simultaneously with the locking of the needle strip and through the closing of the feeler latch is released from the locking position and together with the needle strip is freed to swing downwards into the inoperative position, an axle carrying said swinging arms, the spring acting on the locking lever comprising a helical spring wound on said swinging axle and having portions thereof on both sides of a central operative point forming a movable spring end operatively connected with the locking lever.

References Cited in the tile of this patent UNITED STATES PATENTS 2,446,131 Deck July 27, 1948 FOREIGN PATENTS 163,614 Germany Oct. 28, 1905 "JIM, 

